My mileage runs in the 19's in the summer so long as I behave. Winter mileage drops about 2mpg, I think this is due to the change in gas blends Uncle Sam has forced upon us.
That might have something to do with it but it was also pointed out to me on a pretty professional car website (OK, it was Click and Clack
) that those of us that live in places where we get cold often discount how much more resistance there is in the driveline (lube etc.) until it warms up in the winter and that has a large effect on mileage, especially on shorter trips.
